This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. The subproject and investigator (PI) may have received primary funding from another NIH source, and thus could be represented in other CRISP entries. The institution listed is for the Center, which is not necessarily the institution for the investigator. In order to gain further understanding of the fission yeast SPB, its organization must be determined. Beginning with Ppc89, we plan to build a picture of how this microtubule organizing center is assembled. We already have evidence for direct interaction between Ppc89 and another SPB protein involved in assembling a signaling cascade, Sid4, and now plan to move forward with other sets of FRET partners using these two proteins as vertices.